Vitamin K status, all-cause mortality, and cardiovascular disease in adults with chronic kidney disease: the Chronic Renal Insufficiency Cohort.

BACKGROUND: Vascular calcification contributes to cardiovascular disease (CVD) and mortality in individuals with chronic kidney disease (CKD). Vitamin K-dependent proteins function as calcification inhibitors in vascular tissue. OBJECTIVES: We sought to determine the association of vitamin K status with mortality and CVD events in adults with CKD. METHODS: Plasma dephospho-uncarboxylated matrix gla protein ((dp)ucMGP), which increases when vitamin K status is low, and plasma phylloquinone (vitamin K1), which decreases when vitamin K status is low, were measured in 3066 Chronic Renal Insufficiency Cohort participants (median age = 61 y, 45% female, 41% non-Hispanic black, median estimated glomerular filtration rate [eGFR] = 41 mL/min/1.73m2). The association of vitamin K status biomarkers with all-cause mortality and atherosclerotic-related CVD was determined using multivariable Cox proportional hazards regression. RESULTS: There were 1122 deaths and 599 atherosclerotic CVD events over the median 12.8 follow-up years. All-cause mortality risk was 21-29% lower among participants with plasma (dp)ucMGP <450 pmol/L (n = 2361) compared with those with plasma (dp)ucMGP ≥450 pmol/L (adjusted HRs [95% CIs]: <300 pmol/L = 0.71 [0.61, 0.83], 300-449 pmol/L = 0.77 [0.66, 0.90]) and 16-19% lower among participants with plasma phylloquinone ≥0.50 nmol/L (n = 2421) compared to those with plasma phylloquinone <0.50 nmol/L (adjusted HRs: 0.50, 0.99 nmol/L = 0.84 [0.72, 0.99], ≥1.00 nmol/L = 0.81 [0.70, 0.95]). The risk of atherosclerotic CVD events did not significantly differ across plasma (dp)ucMGP or phylloquinone categories. CONCLUSIONS: Two biomarkers of vitamin K status were associated with a lower all-cause mortality risk but not atherosclerotic CVD events. Additional studies are needed to clarify the mechanism underlying this association and evaluate the impact of improving vitamin K status in people with CKD.

Efficacy and Safety of Expanded Hemodialysis with the Theranova 400 Dialyzer: A Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: Expanded hemodialysis therapy enabled by medium cut-off membranes may promote greater clearance of larger middle molecules that comprise putative uremic solutes than conventional high-flux dialysis. This randomized trial evaluated the efficacy and safety of hemodialysis treatment with a medium cut-off dialyzer. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Clinically stable patients on maintenance hemodialysis were randomized to receive dialysis with either a medium cut-off dialyzer (Theranova 400) or a high-flux dialyzer (Elisio-17H) over 24 weeks of treatment. The primary safety end point was the predialysis serum albumin level after 24 weeks of treatment. The primary efficacy end point was the reduction ratio of free λ light chains at 24 weeks of treatment. RESULTS: Among 172 patients on maintenance hemodialysis, mean age was 59±13 years, 61% were men, 40% were Black, and mean dialysis vintage was 5±4 years. Of the 86 patients randomized to each dialyzer, 65 completed the trial in each group. The reduction ratio for the removal of free λ light chains was significantly higher in the Theranova 400 group compared with the Elisio-17H group after 4 weeks (39% versus 20%) and 24 weeks (33% versus 17%; both P<0.001). Among secondary end points, the Theranova 400 group demonstrated significantly larger reduction ratios at 4 and 24 weeks for complement factor D, free κ light chains, TNFα, and ß2-microglobulin (P<0.001 for all), but not for IL-6. Predialysis serum albumin levels were similar between groups after 24 weeks (4 g/dl with the Theranova 400 and 4.1 g/dl with the Elisio-17H), consistent with noninferiority of the Theranova 400 dialyzer in maintaining predialysis serum albumin levels after 24 weeks of treatment. CONCLUSIONS: Hemodialysis therapy with the Theranova 400 dialyzer provides superior removal of larger middle molecules, as exemplified by free λ light chains, compared with a similar size high-flux dialyzer, while maintaining serum albumin level. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: A Multi-Center, Prospective, Randomized, Controlled, Open-Label, Parallel Study to Evaluate the Safety and Efficacy of the Theranova 400 Dialyzer in End Stage Renal Disease (ESRD) Patients, NCT03257410.

Advance Care Planning Among Older Adults With Advanced Non-Dialysis-Dependent CKD and Their Care Partners: Perceptions Versus Reality?

RATIONALE & OBJECTIVE: Older patients with advanced chronic kidney disease (CKD) use intensive care at the end of life and die in a hospital more frequently than patients with cancer or heart disease. Advance care planning (ACP) can help align treatment with patient preferences and improve patient-centered care, yet ACP quality and experiences among older patients with CKD and their care partners remain incompletely understood, particularly among the non-dialysis-dependent population. STUDY DESIGN: In-person interviewer-administered surveys of patients 70 years and older with non-dialysis-dependent CKD stage 4 or 5 and their self-identified care partners. SETTING & PARTICIPANTS: 42 participants (31 patients, 11 care partners) at 2 clinical sites in greater Boston. OUTCOMES: Completion of advance directives and self-reported perceptions, preferences, and experiences of ACP. ANALYTICAL APPROACH: Descriptive analysis of patient and care partner surveys. McNemar test analysis to compare patient and care partner responses. RESULTS: Most patients had written advance directives (64%) and surrogate decision makers (81%). Although patients reported positive perceptions and high trust in their clinicians' judgment, few (16%) had actually discussed preferences for life-sustaining treatment with their nephrologists. Few ACP discussions included components reflective of high-quality ACP: 16% of patients had been asked about their values concerning end-of-life care and 7% had discussed issues of decision-making capacity and consent to care should their health decline. When presented with 2 hypothetical scenarios (stroke/heart attack or dementia), nearly all patients and care partners reported a preference for comfort care over delaying death. Care partners were more likely than patients to report that they had experienced discussion components reflective of high-quality ACP with the clinical team. LIMITATIONS: Single metropolitan area; most patients did not identify a care partner; nonresponse bias and small sample size. CONCLUSIONS: Patients often believed that their clinicians understood their end-of-life wishes despite not having engaged in ACP conversations that would make those wishes known. Improving clinical ACP communication may result in end-of-life treatment that better aligns with patient goals.

Evaluation of Screening Tests for Cognitive Impairment in Patients Receiving Maintenance Hemodialysis.

BACKGROUND: Neurocognitive testing shows that cognitive impairment is common among patients receiving maintenance hemodialysis. Identification of a well performing screening test for cognitive impairment might allow for broader assessment in dialysis facilities and thus optimal delivery of education and medical management. METHODS: From 2015 to 2018, in a cohort of 150 patients on hemodialysis, we performed a set of comprehensive neurocognitive tests that included the cognitive domains of memory, attention, and executive function to classify whether participants had normal cognitive function versus mild, moderate, or severe cognitive impairment. Using area-under-the-curve (AUC) analysis, we then examined the predictive ability of the Mini Mental State Examination, the Modified Mini Mental State Examination, the Montreal Cognitive Assessment, the Trail Making Test Part B, the Mini-Cog test, and the Digit Symbol Substitution Test, determining each test's performance for identifying severe cognitive impairment. RESULTS: Mean age was 64 years; 61% were men, 39% were black, and 94% had at least a high-school education. Of the 150 participants, 21% had normal cognitive function, 17% had mild cognitive impairment, 33% had moderate impairment, and 29% had severe impairment. The Montreal Cognitive Assessment had the highest overall predictive ability for severe cognitive impairment (AUC, 0.81); a score of ≤21 had a sensitivity of 86% and specificity of 55% for severe impairment, with a negative predictive value of 91%. The Trails B and Digit Symbol tests also performed reasonably well (AUCs, 0.73 and 0.78, respectively). The other tests had lower predictive performances. CONCLUSIONS: The Montreal Cognitive Assessment, a widely available and brief cognitive screening tool, showed high sensitivity and moderate specificity in detecting severe cognitive impairment in patients on maintenance hemodialysis.

Multidisciplinary Medication Therapy Management and Hospital Readmission in Patients Undergoing Maintenance Dialysis: A Retrospective Cohort Study.

RATIONALE & OBJECTIVES: Dialysis patients frequently experience medication-related problems. We studied the association of a multidisciplinary medication therapy management (MTM) with 30-day readmission rates. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Maintenance dialysis patients discharged home from acute-care hospitals between May 2016 and April 2017 who returned to End-Stage Renal Disease Seamless Care Organization dialysis clinics after discharge were eligible. Patients who were readmitted within 3 days, died, or entered hospice within 30 days were excluded. EXPOSURE: MTM consisting of nurse medication reconciliation, pharmacist medication review, and nephrologist oversight was categorized into 3 levels of intensity: no MTM, partial MTM (defined as an incomplete MTM process), or full MTM (defined as a complete MTM process). OUTCOME: The primary outcome was 30-day readmission. ANALYTICAL APPROACH: Time-varying Prentice, Williams, and Peterson total time hazards models explored associations between MTM and time to readmission after adjusting for age, race, sex, diabetes comorbidity, albumin level, vascular access type, kidney failure cause, dialysis vintage and modality, marital status, home medications, frequent prior hospitalizations, length of stay, discharge diagnoses, hierarchical condition category, and facility standardized hospitalization rates. Propensity score matching was performed to examine the robustness of the associations in a comparison between the full- and no-MTM exposure groups on time to readmission. RESULTS: Among 1,452 discharges, 586 received no MTM, 704 received partial MTM, and 162 received full MTM; 30-day readmission rates were 29%, 19%, and 11%, respectively (P < 0.001). Compared with no MTM, discharges with full MTM had the lowest time-varying risk for readmission within 30 days (HR, 0.26; 95% CI, 0.15-0.45); discharges with partial MTM also had lower readmission risk (HR, 0.50; 95% CI, 0.37-0.68). In propensity score-matched sensitivity analysis, full MTM was associated with lower 30-day readmission risk (HR, 0.20; 95% CI, 0.06-0.69). LIMITATIONS: Reliance on observational data. Residual bias and confounding. CONCLUSIONS: MTM services following hospital discharge were associated with fewer 30-day readmissions in dialysis patients. Randomized controlled studies evaluating different MTM delivery models and cost-effectiveness in dialysis populations are warranted.

Cognitive Impairment in CKD: Pathophysiology, Management, and Prevention.

Patients with chronic kidney disease (CKD) are at substantially higher risk for developing cognitive impairment compared with the general population, and both lower glomerular filtration rate and the presence of albuminuria are associated with the development of cognitive impairment and poorer cognitive function. Given the excess of vascular disease seen in individuals with CKD, cerebrovascular disease is likely the predominant pathology underlying these associations, though impaired clearance of uremic metabolites, depression, sleep disturbance, anemia, and polypharmacy may also contribute. Modification of vascular disease risk factors may be helpful in limiting decline, though definite data are lacking. Specific to CKD, targeting a low blood pressure and reduction in albuminuria with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers may slow cognitive decline, albeit modestly. Initiation of dialysis can improve severe impairment associated with uremia but does not appear to affect more subtle chronic cognitive impairment. In contrast, kidney transplantation appears to lead to improved cognitive function in many transplant recipients, suggesting that dialysis methods do not provide the same cognitive benefits as having a functioning kidney. Management of patients with both CKD and cognitive impairment should include a comprehensive plan including more frequent follow-up visits; involvement of family in shared decision making; measures to improve compliance, such as written instruction and pill counts; and a focus on advance directives in conjunction with an emphasis on understanding an individual patient's life goals. Further research is needed on novel therapies, including innovative dialysis methods, that aim to limit the development of cognitive impairment, slow decline in those with prevalent impairment, and improve cognitive function.

Albuminuria and Allograft Failure, Cardiovascular Disease Events, and All-Cause Death in Stable Kidney Transplant Recipients: A Cohort Analysis of the FAVORIT Trial.

RATIONALE & OBJECTIVE: Cardiovascular disease (CVD) is common and overall graft survival is suboptimal among kidney transplant recipients. Although albuminuria is a known risk factor for adverse outcomes among persons with native chronic kidney disease, the relationship of albuminuria with cardiovascular and kidney outcomes in transplant recipients is uncertain. STUDY DESIGN: Post hoc longitudinal cohort analysis of the Folic Acid for Vascular Outcomes Reduction in Transplantation (FAVORIT) Trial. SETTING & PARTICIPANTS: Stable kidney transplant recipients with elevated homocysteine levels from 30 sites in the United States, Canada, and Brazil. PREDICTOR: Urine albumin-creatinine ratio (ACR) at randomization. OUTCOMES: Allograft failure, CVD, and all-cause death. ANALYTICAL APPROACH: Multivariable Cox models adjusted for age; sex; race; randomized treatment allocation; country; systolic and diastolic blood pressure; history of CVD, diabetes, and hypertension; smoking; cholesterol; body mass index; estimated glomerular filtration rate (eGFR); donor type; transplant vintage; medications; and immunosuppression. RESULTS: Among 3,511 participants with complete data, median ACR was 24 (Q1-Q3, 9-98) mg/g, mean eGFR was 49±18 (standard deviation) mL/min/1.73m2, mean age was 52±9 years, and median graft vintage was 4.1 (Q1-Q3, 1.7-7.4) years. There were 1,017 (29%) with ACR < 10mg/g, 912 (26%) with ACR of 10 to 29mg/g, 1,134 (32%) with ACR of 30 to 299mg/g, and 448 (13%) with ACR ≥ 300mg/g. During approximately 4 years, 282 allograft failure events, 497 CVD events, and 407 deaths occurred. Event rates were higher at both lower eGFRs and higher ACR. ACR of 30 to 299 and ≥300mg/g relative to ACR < 10mg/g were independently associated with graft failure (HRs of 3.40 [95% CI, 2.19-5.30] and 9.96 [95% CI, 6.35-15.62], respectively), CVD events (HRs of 1.25 [95% CI, 0.96-1.61] and 1.55 [95% CI, 1.13-2.11], respectively), and all-cause death (HRs of 1.65 [95% CI, 1.23-2.21] and 2.07 [95% CI, 1.46-2.94], respectively). LIMITATIONS: No data for rejection; single ACR assessment. CONCLUSIONS: In a large population of stable kidney transplant recipients, elevated baseline ACR is independently associated with allograft failure, CVD, and death. Future studies are needed to evaluate whether reducing albuminuria improves these outcomes.

Safety and cardiovascular efficacy of spironolactone in dialysis-dependent ESRD (SPin-D): a randomized, placebo-controlled, multiple dosage trial.

The safety and efficacy of spironolactone is uncertain in end-stage renal disease. We randomized 129 maintenance hemodialysis patients to placebo (n=51) or spironolactone 12.5 mg (n=27), 25 mg (n=26), or 50 mg (n=25) daily for 36 weeks in a double-blind, placebo-controlled, multiple dosage trial to assess safety, tolerability and feasibility and to explore cardiovascular efficacy. The primary safety endpoints were hyperkalemia (potassium > 6.5 mEq/L) and hypotension requiring emergency department visit or hospitalization. Diastolic function was assessed by Doppler echocardiography. 125 participants (97%) completed dose escalation, with no significant difference in permanent study drug discontinuation between the groups (27.5% in placebo versus 16.7% in the combined spironolactone groups and 28% in the 50 mg group). Hyperkalemia frequency was similar between spironolactone and placebo (0.49 versus 0.50 events per patient-year) but demonstrated a significant linear trend due primarily to an increased event rate at the 50 mg dose (0.89 events per patient-year). The primary hypotension outcome was infrequent and similar with spironolactone and placebo (0.11 versus 0 events per patient-year). Gynecomastia was rare and did not differ significantly between groups. Change in diastolic function was similar with spironolactone and placebo. Spironolactone appears safe in carefully monitored maintenance hemodialysis patients, but did not affect cardiovascular parameters in this small study. Hyperkalemia occurs more frequently as dosage increases to 50 mg daily.

Smoking and outcomes in kidney transplant recipients: a post hoc survival analysis of the FAVORIT trial.

BACKGROUND: Tobacco use remains an international health problem with between 10% and 40% of adults currently using tobacco. Given the rising number of patients either awaiting or having received a kidney transplant and the absence of smoking cessation as the criterion for transplantation in guidelines, we explored the association between smoking status and clinical outcomes in kidney transplant recipients. PATIENTS AND METHODS: In this post hoc analysis of the Folic Acid for Vascular Outcome Reduction in Transplant trial, the associations between smoking status, defined as never having smoked, formerly or currently smoking, and both all-cause mortality and graft survival were assessed using Cox proportional hazards models. Fatal events were centrally adjudicated into prespecified categories: all-cause, cardiovascular and non-cardiovascular causes. Graft loss was defined as return to dialysis or retransplantation. Clinical Trials URL: http://www.clinicaltrials.gov/show/NCT00064753. RESULTS: Among 4110 transplant recipients, there were 451 current smokers and 1611 former smokers. The mortality rate per 100 patient-years was 4.0 (71 deaths) for smokers, 3.5 (226 deaths) for former smokers and 2.4 (116 deaths) for never smokers. Hazard ratio for mortality for current smokers was 1.70 (CI=1.26-2.29, p=0.001) and for former smokers was 1.21 (0.98-1.50, p=0.08) with 1.0 representing never smokers. As the number of cardiovascular deaths was similar in each group (all p>0.3), the differences between groups was driven by non-cardiovascular death rates. Current smokers (2.39; 1.62-3.61, p<0.001) and former smokers (1.50; 1.12-2.01, p=0.007) had increased hazard of non-cardiovascular death. Kidney allograft failure was more likely in current smokers than in either former or never smokers (3.5, 2.1 and 2.0 per 100 patient-years, p<0.001, adjusted hazard ratio 1.49 and 1.05, respectively). CONCLUSION: Continued smoking was associated with >100% increased risk of non-cardiovascular death, 70% greater risk of all-cause mortality and a 50% greater risk of graft loss, a risk not seen in former smokers. These findings confirm previous non-adjudicated observations that smoking is associated with adverse clinical outcomes and suggest that more emphasis should be placed on smoking cessation prior to kidney transplantation.

Serum Uromodulin: A Biomarker of Long-Term Kidney Allograft Failure.

BACKGROUND: Uromodulin is a kidney-derived glycoprotein and putative tubular function index. Lower serum uromodulin was recently associated with increased risk for kidney allograft failure in a preliminary, longitudinal single-center -European study involving 91 kidney transplant recipients (KTRs). METHODS: The Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) trial is a completed, large, multiethnic controlled clinical trial cohort, which studied chronic, stable KTRs. We conducted a case cohort analysis using a randomly selected subset of patients (random subcohort, n = 433), and all individuals who developed kidney allograft failure (cases, n = 226) during follow-up. Serum uromodulin was determined in this total of n = 613 FAVORIT trial participants at randomization. Death-censored kidney allograft failure was the study outcome. RESULTS: The 226 kidney allograft failures occurred during a median surveillance of 3.2 years. Unadjusted, weighted Cox proportional hazards modeling revealed that lower serum uromodulin, tertile 1 vs. tertile 3, was associated with a threefold greater risk for kidney allograft failure (hazards ratio [HR], 95% CI 3.20 [2.05-5.01]). This association was attenuated but persisted at twofold greater risk for allograft failure, after adjustment for age, sex, smoking, allograft type and vintage, prevalent diabetes mellitus and cardiovascular disease (CVD), total/high-density lipoprotein cholesterol ratio, systolic blood pressure, estimated glomerular filtration rate, and natural log urinary albumin/creatinine: HR 2.00, 95% CI (1.06-3.77). CONCLUSIONS: Lower serum uromodulin, a possible indicator of less well-preserved renal tubular function, remained associated with greater risk for kidney allograft failure, after adjustment for major, established clinical kidney allograft failure and CVD risk factors, in a large, multiethnic cohort of long-term, stable KTRs.

Hyperuricemia, Acute and Chronic Kidney Disease, Hypertension, and Cardiovascular Disease: Report of a Scientific Workshop Organized by the National Kidney Foundation.

Urate is a cause of gout, kidney stones, and acute kidney injury from tumor lysis syndrome, but its relationship to kidney disease, cardiovascular disease, and diabetes remains controversial. A scientific workshop organized by the National Kidney Foundation was held in September 2016 to review current evidence. Cell culture studies and animal models suggest that elevated serum urate concentrations can contribute to kidney disease, hypertension, and metabolic syndrome. Epidemiologic evidence also supports elevated serum urate concentrations as a risk factor for the development of kidney disease, hypertension, and diabetes, but differences in methodologies and inpacts on serum urate concentrations by even subtle changes in kidney function render conclusions uncertain. Mendelian randomization studies generally do not support a causal role of serum urate in kidney disease, hypertension, or diabetes, although interpretation is complicated by nonhomogeneous populations, a failure to consider environmental interactions, and a lack of understanding of how the genetic polymorphisms affect biological mechanisms related to urate. Although several small clinical trials suggest benefits of urate-lowering therapies on kidney function, blood pressure, and insulin resistance, others have been negative, with many trials having design limitations and insufficient power. Thus, whether uric acid has a causal role in kidney and cardiovascular diseases requires further study.

Toward Establishing Core Outcome Domains For Trials in Kidney Transplantation: Report of the Standardized Outcomes in Nephrology-Kidney Transplantation Consensus Workshops.

BACKGROUND: Treatment decisions in kidney transplantation requires patients and clinicians to weigh the benefits and harms of a broad range of medical and surgical interventions, but the heterogeneity and lack of patient-relevant outcomes across trials in transplantation makes these trade-offs uncertain, thus, the need for a core outcome set that reflects stakeholder priorities. METHODS: We convened 2 international Standardized Outcomes in Nephrology-Kidney Transplantation stakeholder consensus workshops in Boston (17 patients/caregivers; 52 health professionals) and Hong Kong (10 patients/caregivers; 45 health professionals). In facilitated breakout groups, participants discussed the development and implementation of core outcome domains for trials in kidney transplantation. RESULTS: Seven themes were identified. Reinforcing the paramount importance of graft outcomes encompassed the prevailing dread of dialysis, distilling the meaning of graft function, and acknowledging the terrifying and ambiguous terminology of rejection. Reflecting critical trade-offs between graft health and medical comorbidities was fundamental. Contextualizing mortality explained discrepancies in the prioritization of death among stakeholders-inevitability of death (patients), preventing premature death (clinicians), and ensuring safety (regulators). Imperative to capture patient-reported outcomes was driven by making explicit patient priorities, fulfilling regulatory requirements, and addressing life participation. Specificity to transplant; feasibility and pragmatism (long-term impacts and responsiveness to interventions); and recognizing gradients of severity within outcome domains were raised as considerations. CONCLUSIONS: Stakeholders support the inclusion of graft health, mortality, cardiovascular disease, infection, cancer, and patient-reported outcomes (ie, life participation) in a core outcomes set. Addressing ambiguous terminology and feasibility is needed in establishing these core outcome domains for trials in kidney transplantation.

Circulating Vitamin K Is Inversely Associated with Incident Cardiovascular Disease Risk among Those Treated for Hypertension in the Health, Aging, and Body Composition Study (Health ABC).

Background: A role for vitamin K in coronary artery calcification (CAC), a subclinical manifestation of cardiovascular disease (CVD), has been proposed because vitamin K-dependent proteins, including the calcification inhibitor matrix Gla protein (MGP), are present in vascular tissue. Observational studies found that low circulating phylloquinone (vitamin K-1) was associated with increased CAC progression, especially in persons treated for hypertension. It is unknown whether hypertension treatment modifies this putative role of vitamin K in clinical CVD risk.Objective: We determined the association between vitamin K status and incident clinical CVD in older adults in the Health ABC (Health, Aging, and Body Composition Study) and whether the association differed by hypertension treatment status.Methods: Plasma phylloquinone was measured in 1061 participants free of CVD (70-79 y of age, 58% women, 39% black). Plasma uncarboxylated MGP [(dp)ucMGP] was measured in a subset of 635 participants. Multivariate Cox models estimated the HR for incident CVD over 12.1 follow-up years. Effect modification by hypertension was tested with the use of interaction terms.Results: Neither low plasma phylloquinone (<0.2 nmol/L) nor elevated (dp)ucMGP (≥574 pmol/L) was significantly associated with incident CVD [respective HRs (95% CIs): 1.27 (0.75, 2.13) and 1.02 (0.72, 1.45)]. In participants treated for hypertension (n = 489; 135 events), low plasma phylloquinone was associated with higher CVD risk overall (HR: 2.94; 95% CI: 1.41, 6.13). In those with untreated hypertension (n = 153; 48 events) and without hypertension (n = 418; 92 events), low plasma phylloquinone was not associated with incident CVD. The association between high (dp)ucMGP did not differ by hypertension treatment status (P-interaction = 0.72).Conclusions: Vitamin K status was not significantly associated with CVD risk overall, but low plasma phylloquinone was associated with a higher CVD risk in older adults treated for hypertension. Additional evidence from larger clinical studies is needed to clarify the importance of vitamin K to CVD in persons treated for hypertension, a segment of the population at high risk of clinical CVD events.

Leptospira seropositivity as a risk factor for Mesoamerican Nephropathy.

BACKGROUND: Leptospirosis is postulated as a possible cause of Mesoamerican Nephropathy (MeN) in Central American workers. OBJECTIVES: Investigate job-specific Leptospira seroprevalence and its association with kidney disease biomarkers. METHODS: In 282 sugarcane workers, 47 sugarcane applicants and 160 workers in other industries, we measured anti-leptospiral antibodies, serum creatinine, and urinary injury biomarkers, including neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), and N-acetyl-D-glucosaminidase (NAG). RESULTS: Leptospira seroprevalence differed among job categories and was highest among sugarcane cutters (59%). Seropositive sugarcane workers had higher NGAL concentrations (relative mean: 1.28; 95% CI: 0.94-1.75) compared to those who were seronegative, with similar findings among field and non-field workers. CONCLUSIONS: Leptospira seroprevalence varied by job category. There was some indication that seropositivity was associated with elevated biomarker levels, but results were inconsistent. Additional studies may help establish whether Leptospira infection plays any role in MeN among Central American workers.

Vascular imaging for hemodialysis vascular access planning.

INTRODUCTION: Central venous catheters (CVC) increase risks associated with hemodialysis (HD), but may be necessary until an arteriovenous fistula (AVF) or graft (AVG) is achieved. The impact of vascular imaging on achievement of working AVF and AVG has not been firmly established. METHODS: Retrospective cohort of patients initiating HD with CVC in 2010-2011, classified by exposure to venography or Doppler vein mapping, and followed through December 31, 2012. Standard and time-dependent Cox models were used to determine hazard ratios (HRs) of death, working AVF, and any AVF or AVG. Logistic regression was used to assess the association of preoperative imaging with successful AVF or AVG among 18,883 individuals who had surgery. Models were adjusted for clinical and demographic factors. FINDINGS: Among 33,918 patients followed for a median of 404 days, 39.1% had imaging and 55.7% had surgery. Working AVF or AVG were achieved in 40.6%; 46.2% died. Compared to nonimaged patients, imaged patients were more likely to achieve working AVF (HR = 1.45 [95% confidence interval [CI] 1.36, 1.55], P < 0.001]), any AVF or AVG (HR = 1.63 [1.58, 1.69], P > 0.001), and less likely to die (HR = 0.88 [0.83-0.94], P < 0.001). Among patients who had surgery, the odds ratio for any successful AVF or AVG was 1.09 (1.02-1.16, P = 0.008). DISCUSSION: Fewer than half of patients who initiated HD with a CVC had vascular imaging. Imaged patients were more likely to have vascular surgery and had increased achievement of working AV fistulas and grafts. Outcomes of surgery were similar in patients who did and did not have imaging.

Urine Fibrosis Markers and Risk of Allograft Failure in Kidney Transplant Recipients: A Case-Cohort Ancillary Study of the FAVORIT Trial.

BACKGROUND: Kidney tubulointerstitial fibrosis marks risk for allograft failure in kidney transplant recipients, but is poorly captured by estimated glomerular filtration rate (eGFR) or urine albumin-creatinine ratio (ACR). Whether urinary markers of tubulointerstitial fibrosis can noninvasively identify risk for allograft failure above and beyond eGFR and ACR is unknown. STUDY DESIGN: Case-cohort study. SETTING & PARTICIPANTS: The FAVORIT (Folic Acid for Vascular Outcome Reduction in Transplantation) Trial was a randomized double-blind trial testing vitamin therapy to lower homocysteine levels in stable kidney transplant recipients. We selected a subset of participants at random (n=491) and all individuals with allograft failure during follow-up (cases; n=257). PREDICTOR: Using spot urine specimens from the baseline visit, we measured 4 urinary proteins known to correlate with tubulointerstitial fibrosis on biopsy (urine α1-microglobulin [A1M], monocyte chemoattractant protein 1 [MCP-1], and procollagen type III and type I amino-terminal amino pro-peptide). OUTCOME: Death-censored allograft failure. RESULTS: In models adjusted for demographics, chronic kidney disease risk factors, eGFR, and ACR, higher concentrations of urine A1M (HR per doubling, 1.73; 95% CI, 1.43-2.08) and MCP-1 (HR per doubling, 1.60; 95% CI, 1.32-1.93) were strongly associated with allograft failure. When additionally adjusted for concentrations of other urine fibrosis and several urine injury markers, urine A1M (HR per doubling, 1.76; 95% CI, 1.27-2.44]) and MCP-1 levels (HR per doubling, 1.49; 95% CI, 1.17-1.89) remained associated with allograft failure. Urine procollagen type III and type I levels were not associated with allograft failure. LIMITATIONS: We lack kidney biopsy data, BK titers, and HLA antibody status. CONCLUSIONS: Urine measurement of tubulointerstitial fibrosis may provide a noninvasive method to identify kidney transplant recipients at higher risk for future allograft failure, above and beyond eGFR and urine ACR.

Risk of renal cell carcinoma following exposure to metalworking fluids among autoworkers.

OBJECTIVES: Metalworking fluids (MWF), used to cool and lubricate metal in occupational settings, are linked to several cancers but data on kidney cancer are limited. We examine how MWF influence the rate of renal cell carcinoma (RCC) in a large prospective study. METHODS: A cohort of Michigan autoworkers consisting of 33 421 individuals was followed from 1985 to 2009. The cohort was linked to the Michigan Cancer Registry to identify new cases of RCC. We analysed RCC in relation to cumulative exposure to each specific type of MWF (straight, soluble and synthetic) and all 3 types pooled into a single MWF variable, with a 15-year lag. Cox proportional hazards regression with splines were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs), controlling for age, gender, race, calendar year, year hired, time since hire, plant and other MWF types. RESULTS: There were 135 incident cases. A linear increase in the log-HR was observed for RCC with increasing cumulative exposure to each MWF type and total MWF exposure. At the mean of total MWF exposure (18.80 mg/m(3)-year), the estimated HR was 1.11 (95% CI 1.04 to 1.19). CONCLUSIONS: Our results provide evidence for a dose-dependent association between MWF exposure and RCC. The influence of components of oil-based and water-based MWF needs further examination.

A palliative approach to dialysis care: a patient-centered transition to the end of life.

As the importance of providing patient-centered palliative care for patients with advanced illnesses gains attention, standard dialysis delivery may be inconsistent with the goals of care for many patients with ESRD. Many dialysis patients with life expectancy of <1 year may desire a palliative approach to dialysis care, which focuses on aligning patient treatment with patients' informed preferences. This commentary elucidates what comprises a palliative approach to dialysis care and describes its potential and appropriate use. It also reviews the barriers to integrating such an approach into the current clinical paradigm of care and existing infrastructure and outlines system-level changes needed to accommodate such an approach.